1. Field of the Invention
The present invention relates generally to entertainment and architectural lighting, and more specifically is a device to control the hue and saturation of color emanating from a lighting fixture.
2. Description of the Prior Art
Colored light sources are often used in the theater, television, touring productions, and architectural applications. The projected light color is varied in hue, saturation level, beam size, and/or focus to obtain a particular desired artistic effect. The requirements of the effect might be that the color and/or focus remain static, or that the color and/or focus change over time. Factors that must be considered when choosing a color changing lighting system to create various effects are cost, the quantity of colors to be produced, the smoothness of color transition, size and weight of the lighting units, and the efficiency of light transmission through the color filters. The system must also provide smooth distribution of the light and the color when the light beam is projected onto a surface.
The prototypical current art system is illustrated in U.S. Pat. No. 4,914,556, by the present inventor Richardson, issued Apr. 3, 1990. Over the years, the method disclosed in the Richardson patent for changing colors produced by a lighting module has been adopted in some form by most of the major manufacturers of lighting equipment. A schematic representation of the Richardson current art system is shown in FIG. 1.
The Richardson color changing system 1 is capable of producing a great number of colors by introducing into the light path in varying degrees yellow, cyan, and/or magenta filters 2. These filters 2 are coated type filters with a gradient from nearly clear to fully saturated. A light source with a reflector 3 generates a light beam 4. The light beam 4 is directed toward a focal point 5, beyond which the light beam 4 passes through an aperture 6. After the light beam 4 passes through the aperture 6, it is directed toward the desired object by an image lens 7.
One drawback of the system disclosed in Richardson is that the percentage of light transmission is low when pastel colors are created. This factor can lead to an unsatisfactory lighting effect when pastel colors are utilized.
Another shortcoming is that due to the order of placement of the elements, the image lens 7 used in the Richardson system needs to be of a substantial size. Large lenses are costly. Moreover, large lenses do not produce a projected image with as high quality as is produced by a smaller lens.
Finally, the length of the optical path for the defined prior art system 1, again, due to the chosen order of placement, is quite substantial. The length of the optical path mandates that a lighting unit embodying this system be relatively large.
Accordingly, it is an object of the present invention to provide a lighting system that creates a vivid emitted light beam for saturated and pastel colors.
It is another object of the present invention to provide a lighting system that produces colored light beams with improved image quality.
It is still another object of the present invention to provide a lighting system that can be implemented in a compact package.